Mathematical economics is the sub-field of economics that explores the mathematical aspects of economic systems. Modern mainstream economic research typically makes extensive use of mathematical modelling. As a result, the distinction between mathematical and non-mathematical economics is less clear today than it once was.

Mathematical economics can be regarded as the "theoretical" counterpart of Econometrics, which attempts to analyse the real world of economic activity using statistical techniques.

The mathematical tools economists use are often applied in other sciences as well.